Since the inception of computer networks, the size of networks has grown exponentially. Today, any number of computing devices may be connected over a network, and data and services provided by those devices may be accessed from any number of locations. With that growth, the complexity of managing storage solutions across networks has increased.
In non-virtualized computing devices, the files are accessed either via distributed file system like NFA or SAMBA/CIFS or via locally attached block device with its own file system. Virtualization trend in compute and networking require storage virtualization where different solutions are sometimes called Software Defined Storage. SDS could offer coarse-grained bottom-up abstractions (box, volume, LUN, filesystem) vs. fine-grained top-down abstractions for data management (virtual machines, virtual disks) required for a multi-tenant cloud environment. SDS is a part of the broader software-defined data center concept wherein all the virtualized storage, server, networking and security resources required by an application can be defined by software and provisioned automatically.